USC professor Henry Jenkins coined the term to explain how an array of platforms can be used to enrich media's impact on the public.

Professor Henry Jenkins raised this topic in his very first class at USC three months ago.

The benches refer to advertisements for "District 9" placed at bus stops nationwide, with the tag line "Bus bench for humans only," playing on the science-fiction film's apartheid allegory. Jenkins argues that the benches are also examples of "transmedia storytelling," the topic of the course and a reason why the media scholar moved to USC after a high-profile run at the Massachusetts Institute of Technology.

"I spent the first 20 years of my academic life at MIT in the midst of the digital revolution, and I thought it would be fascinating to spend the second 20 years in Hollywood, observing the other side of the equation," he says. Jenkins -- officially the provost's professor of communication, journalism and cinematic arts -- researches how audiences engage with media through the Internet, fan fiction and video games. In books such as "Textual Poachers" and "Convergence Culture," he delves into various audience subcultures, from heated online forums that try to predict the winner of "Survivor" to "slash fiction" stories that interpret "Star Trek" characters as bisexuals. He is writing a book on "spreadable media," touching on phenomena like Susan Boyle and Twitter as a protest tool in Iran.

Larry Gross, director of the school of communication at USC, who helped recruit Jenkins, says that media studies scholars often have "a kind of contempt for the audience." Jenkins, Gross adds, "is someone who views the audience as active participants and creative participants, who don't simply accept what is happening to them."

Audiences are especially active in what Jenkins dubs "transmedia" storytelling, in which a story spans multiple media in a coordinated way. In the traditional Hollywood model, the novelization, video game or website simply restates the characters or the plot of a film or a TV show. In transmedia stories, the creators of the entertainment will use those extensions to, say, fill in the gaps in a narrative or look at events from a minor character's point of view -- all of which combine into one big story that audiences have to piece together. "It appeals to the hunting-and-gathering impulses of fans," Jenkins says. For instance, "District 9" has online documentaries, websites for fake alien-rights organizations and, yes, benches, all of which help drive home the human-alien divide in the film's fictional Johannesburg. "Those benches are designed to shape our experience of the film," Jenkins says. "They're not just designed to get us into the theater."

Transmedia has its antecedents in the serialized fiction of Charles Dickens and the interlocking characters and locations of William Faulkner's fictional Yoknapatawpha County. Superheroes like Superman, created in the 1930s, came closer, appearing in comic books, radio and live-action serials but without coordination from a central creative force.

Jenkins coined the term around the time of "The Blair Witch Project," which used fake online documentary footage to market the movie. Nowadays, unveiling a story through multiple media is a common practice, ranging from TV series such as "Flash Forward" and "Melrose Place" to the campaign of Barack Obama.

CBS' "Ghost Whisperer" has fueled a following through comic books, online games and Web series such as "The Other Side," which looks at the world of the show from the ghost's perspective. "We let those offshoots give the audience their own personal experience," says Kim Moses, an executive producer of the show, who spoke to Jenkins' class. "Had we not done all this stuff, that show would not make it to the fifth year."

A seminal transmedia moment for Jenkins came in a scene in "The Matrix Reloaded," when "The Kid" has a conversation with Neo (Keanu Reeves) that is rather cryptic -- unless you've seen the Kid introduced in "The Animatrix," a series of animated shorts.

Jenkins acknowledges that transmedia has its challenges. Does it exclude moviegoers who just want their films to begin when they enter the multiplex and end two hours later? What if some people watch the TV show first and the webisode second, when the reverse would be much more gratifying? And can the satisfaction of piecing together these bits of storytelling ever measure up to the simple pleasure of watching the hero defeat the bad guys? "It may be that you try some interesting stuff," Jenkins says, "but at the end of the day, our grandest ambitions aren't going to be realizable."

Tapping potential

Jenkins' study of audiences goes beyond pop culture. His other class this semester is on new media literacy, an area where he applies what he knows about audiences to improving education.